In America, millions of workers are exposed to vibration from machinery and powered tools. Prolonged exposure to excessive, hand transmitted vibration causes debilitating, often permanent, vascular, neural and musculoskeletal problems. Our long-term goal is to understand the mechanism of vibration injury at the cellular and molecular levels in order to define strategies for monitoring and preventing hand arm vibration syndrome. These studies help to improve the health, safety and welfare of workers exposed to hazardous vibration. A rat tail vibration, model of acute and chronic vibration disease is utilized for characterizing the primary lesion(s), disease progression and irreversible injury of the musculoskeletal, vascular and neural systems. The 4 aims are 1) to demonstrate that the short and long duration effects of vibration involve endothelial cell loss and the proliferation and in growth of smooth muscles cells, which progress to occlusion of the arterial blood vessel lumen resulting in impeded blood flow and to ascertain whether injury susceptibility of specific cell types is frequency and acceleration dependent, 2) to demonstrate that vibration produces progressive disruptions of peripheral nerves, which result in compromised nerve conduction and impaired retrograde axoplasmic transport and to ascertain whether injury susceptibility is frequency and acceleration dependent, 3) to correlate cell type specific, structural damage with serum immunoassays and enzyme activity assays of the amounts of neural, vascular and skeletal muscle cell specific, proteins released into the blood following vibration injury and to develop a means of minimally invasive monitoring of vibration injury, and 4) to characterize at 1, 2 and 3 months after stopping long term vibration, the structural states of arteries and nerves, when blood flow is severely obstructed and nerve conduction is depressed. The results of these studies will further the understanding of the pathogenesis of vibration disease and provide insights into novel monitoring, treatment and preventative strategies. ? ?
| Krajnak, Kristine; Riley, Danny A; Wu, John et al. (2012) Frequency-dependent effects of vibration on physiological systems: experiments with animals and other human surrogates. Ind Health 50:343-53 |
| Raju, Sandya Govinda; Rogness, Olaf; Persson, Magnus et al. (2011) Vibration from a riveting hammer causes severe nerve damage in the rat tail model. Muscle Nerve 44:795-804 |
| Loffredo, Michael A; Yan, Ji-Geng; Kao, Dennis et al. (2009) Persistent reduction of conduction velocity and myelinated axon damage in vibrated rat tail nerves. Muscle Nerve 39:770-5 |
| Govindaraju, Sandya R; Bain, James Lw; Eddinger, Thomas J et al. (2008) Vibration causes acute vascular injury in a two-step process: vasoconstriction and vacuole disruption. Anat Rec (Hoboken) 291:999-1006 |
